The state list is now at 26. Where is Tilted!
If you're asking whether these states can refuse to allow refugees in, the answer is with little doubt: No. Statements by governors to the effect that their states won't accept the refugees are mostly just hollow political rhetoric. They frame their declarations that way to score political points as they know, because it's been pretty clearly established, that the federal government gets to decide who can or can't enter the country. And they can't stop people that are here from coming to their states, or even from being brought there by the federal government. In other words, some of the governors are grandstanding.
Now, to be clear, some of the governors may sincerely (though misguidedly I think - but I'll leave that aspect of the situation for another conversation) believe that in the wake of what happened in Paris we shouldn't allow these refugees into our country and they may well not want any of those refugees in their own states. I'm not suggesting that they are just making up their concerns or that they wouldn't, if they could, stop these refugees from coming in. But they most likely know that they can't and that their own declarations suggesting that they will have no legal effect, that they just have rhetorical effect.
What states can do is refuse to assist the federal government when it comes to settling refugees. Some of the governors have indicated that they will indeed do that. They don't necessarily have to use state resources to help with these refugees, that's the states' choice. I suspect there are plenty of private parties that will be willing to assist with refugee settlement. The governors can also, as many of them have, ask the President to reconsider his decision to allow these refugees in. But beyond that, there isn't much they can do to stop him or to stop the refugees, once here with refugee status, from settling in particular states.